气候变化领域集成服务门户(CCPortal): Differences in leaf physiology among juvenile pines and oaks following high-severity wildfire in an Arizona Sky Island Mountain range

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DOI	10.1016/j.foreco.2019.117704
	Differences in leaf physiology among juvenile pines and oaks following high-severity wildfire in an Arizona Sky Island Mountain range
	Poulos H.M.; Barton A.M.; Berlyn G.P.; Schwilk D.W.; Faires C.E.; McCurdy W.C.
发表日期	2020
ISSN	0378-1127
卷号	457
英文摘要	Recent increases in wildfire severity are converting pine-oak (Pinus-Quercus) woodland to oak shrubland in many sites in the southwestern United States. A key mechanism underlying this transition is the vigorous resprouting capacity of oaks compared to low regeneration rates in pines following wildfire. Differences among species in leaf physiological characteristics may also contribute to such vegetation type conversions, especially in the context of recent increased regional aridity. To that end, we evaluated variation in leaf functional traits in post-fire recruits five years after the 2011 Horseshoe Two in the Chiricahua Mountains, Arizona, USA. We measured a suite of functional traits in two pines (Pinus engelmannii and P. leiophylla) and two oaks (Quercus hypoleucoides and Q. arizonica), including leaf gas exchange, leaf pigment concentrations, leaf spectral reflectance, and wood xylem δ13C, δ18O isotopes, and integrated water use efficiency (iWUE). The four study species displayed a range of plant functional traits tied to desiccation tolerance. P. engelmannii seedling recruits presented invariably low maximum photosynthetic rate (Amax), stomatal conductance (gs), and transpiration (E), and high relative leaf water content during the peak of the May-June drought, a response strongly indicative of a desiccation-avoidant leaf that prioritizes water conservation over carbon fixation in arid conditions. In contrast, resprouts of both oaks displayed leaf desiccation tolerance, with high levels of gs and E and low relative leaf water content. Gas exchange in P. leiophylla resprouts was more similar to the oaks, except for relative water content, which was similar to that of P. engelmannii. Compared to the other two species, P. engelmannii and Q. hypoleucoides exhibited significantly higher δ13C, δ18O and iWUE values—a pattern that appears to have arisen from different mechanisms in the two species. In desiccation-avoidant P. engelmannii, low instantaneous gs and high δ18O suggested that low stomatal conductance rather than high photosynthetic rates led to high iWUE, whereas lower δ18O and very high pigment concentrations in Q. hypoleucoides suggest a more important role for Amax in this species. Neither fire severity nor physiography influenced the physiological responses in any of the four species, suggesting that the expression of resprout and seedling functional traits is fixed. These results raise the possibility that differences in leaf physiological characteristics contribute to the regeneration success of some oak species and the poor seedling establishment of obligate seeder pines, such as P. engelmannii, after high-severity wildfire in the American Southwest. © 2019 Elsevier B.V.
英文关键词	Alternative stable states; Ecophysiology; Gas exchange; Isotopes; Oak shrubland; Pine-oak forest; Sky Islands; Southwest USA
语种	英语
scopus关键词	Driers (materials); Fires; Isotopes; Physiological models; Reforestation; Water conservation; Alternative stable state; Ecophysiology; Gas exchange; Oak forests; Shrublands; Sky Islands; Southwest USA; Physiology; aridity; carbon fixation; carbon isotope; coniferous tree; deciduous tree; desiccation; ecophysiology; gas exchange; juvenile; leaf; mixed forest; mountain region; oxygen isotope; photosynthesis; physiological response; regeneration; shrubland; stomatal conductance; transpiration; water content; wildfire; Drying; Fires; Isotopes; Moisture Content; Physiology; Quercus; Reforestation; Water Management; Arizona; Chiricahua Mountains; United States; Pinus engelmannii; Pinus leiophylla; Quercus; Quercus arizonica; Quercus hypoleucoides
来源期刊	Forest Ecology and Management
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/155572
作者单位	College of the Environment, Wesleyan University, 284 High St., Middletown, CT 06459, United States; Department of Biology, University of Maine at Farmington, Farmington, ME 04938, United States; Yale School of Forestry and Environmental Studies, New Haven, CT 06511, United States; Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, United States; Department of Forest Resources and Environmental Conservation, Virginia Tech, Blacksburg, VA 24061, United States
推荐引用方式 GB/T 7714	Poulos H.M.,Barton A.M.,Berlyn G.P.,et al. Differences in leaf physiology among juvenile pines and oaks following high-severity wildfire in an Arizona Sky Island Mountain range[J],2020,457.
APA	Poulos H.M.,Barton A.M.,Berlyn G.P.,Schwilk D.W.,Faires C.E.,&McCurdy W.C..(2020).Differences in leaf physiology among juvenile pines and oaks following high-severity wildfire in an Arizona Sky Island Mountain range.Forest Ecology and Management,457.
MLA	Poulos H.M.,et al."Differences in leaf physiology among juvenile pines and oaks following high-severity wildfire in an Arizona Sky Island Mountain range".Forest Ecology and Management 457(2020).